Excerpt / Summary LADEE impacted the far side of the Moon on 18 April, confirmed by ground control at 6:59 UT (2:59 a.m. EDT).
The Lunar Atmosphere and Dust Environment Explorer (LADEE) launched 07 September 2013 at 03:27 UT (06 September 11:27 EDT) on a Minotaur-V from Wallops Flight Facility. LADEE is designed to characterize the tenuous lunar atmosphere and dust environment from orbit. The scientific objectives of the mission are:(1) determine the global density, composition, and time variability of the fragile lunar atmosphere; and, (2) determine the size, charge, and spatial distribution of electrostatically transported dust grains and assess their likely effects on lunar exploration and lunar-based astronomy. Further objectives are to determine if the Apollo astronaut sightings of diffuse emission at 10s of km above the surface were Na glow or dust and document the dust impactor environment (size-frequency) to help guide design engineering for outpost and future robotic missions.
Launch occured as scheduled on 06 September 2013 at 11:27 EDT (07 September 03:27 UTC). After a 30 day phasing orbit to reach nominal lunar orbit and a 30 day checkout period, the 100-day nominal science orbit will begin. The orbiter will carry a Neutral Mass Spectrometer (NMS), an Ultraviolet/Visible Spectrometer (UVS), and a Lunar Dust Experiment (LDEX). There is also a technology demonstration, the Lunar Laser Communications Demonstration (LLCD). Spacecraft communications will be via S-band with a 10 Kbps science data rate. The spacecraft is basically a 1.85 meter-diameter cylinder with a height of 2.37 meters. Total mass of the orbiter is approximately 383 kg, which includes 135 kg of fuel, with solar array panels covering the outside surface producing 295 Watts at 1 AU..
The instruments will detect and constrain the abundances of species expected to be prevalent at and below the 50 km altitude, due to the solar wind and its interactions with the surface, release from regolith, and radiogenic sources. The NMS is a quadrupole mass spectrometer designed ot detect species up to 150 amu and will look for CH4, S, O, Si, Kr, Xe, Fe, Al, Ti, Mg, OH, and H2O. The UVS will detect Al, Ca, Fe, K, Li, Na, Si, T, Ba, Mg, H2O, and O and will monitor the dust composition. The LDEX is an impact ionization dust detector designed to measure particles down to 0.3 microns at the spacecraft altitude. The LLCD is a test of a high data-rate optical (laser) communications system.
After launch on the Minotaur V with a Star 48BV 4th stage and a Star 37FM upper stage, LADEE entered an elliptical Earth orbit which will be elongated by perigee boosts until it can perform a lunar orbit insertion on 6 October. It will then spend 30 days reaching nominal lunar orbit and checking out systems before its nominal 100 day science mission starts. The spacecraft will be put into a near-circular retrograde equatorial science orbit with an altitude of approximately 50 km and the periselene over the dawn terminator.
Total lifetime cost of the mission is approximately $263 million. For more on the LADEE mission, see: |